If you recently installed an ad blocker downloaded from the Chrome store, it may be worthwhile checking to see if it's a fake extension or not. According to a new report from AdGuard, more than 20 million fake ad blockers have been downloaded by unsuspecting users.

The findings also prompted Google to remove five of the top-ranking fake ad blockers from their Chrome store, but how many there are in total is unclear at this stage.

AdGuard says the fake ad blockers utilising additional code within the extension to harvest information from the websites that users visit. Furthermore, they are said to send the data collected to remote servers in order to manipulate the behaviour of Chrome.

"Basically, this is a botnet composed of browsers infected with the fake adblock extensions…  The browser will do whatever the command center server owner orders it to do," noted the AdGuard report.

As for users can better protect themselves from being duped, AdGuard advises people to check the author of the extension to see if it's the name of a company they can trust. Another handy tip is looking at the name of the ad blocker, which are often quite lazily constructed when they're fake.

Whether or not Google can combat this recent epidemic plaguing its browser, remains to be seen.